The conventional method of controlling subsea tree functions has been through a connection method from a remote hydraulic or electrical/hydraulic source acting via a control or umbilical line and an interface plate(s). These interface plates have been disconnected and reconnected in various ways to switch remote operation from a production (or “host”) facility to a vessel overhead during equipment installation and later workover (well intervention). The key to the interfaces is that when in the workover mode, the production mode of operation is locked out, thereby preventing accidental operation by outside sources when critical control of the well is required by the overhead vessel.
The problem in the current art is the installation of the umbilical lines or flying leads in a swift and economical manner.
Typically, flying leads have been installed using a vessel. The length of required flying lead is lowered from a vessel to the sea floor. The ends of the flying lead are picked up by remote operated vehicles and connected at the corresponding trees or junctions. This method requires a vessel to be present the entire time of the install thereby increasing the cost of the project (rent of the vessel plus the crew and the associated costs).
In addition, since the flying leads are often being lowered from a vessel to a seabed at great depths, the risk factor to workers and equipment is increased.
A need exists for an apparatus that can be deployed on a seabed and then deploy a predetermined length of flying lead without the need of a vessel to be present.